The furthest or highest degree of something.

ETYM Latin extremus, superl. of exter, extrus, on the outside, outward: cf. French extręme. Related to Exterior.
1. Beyond a norm in views or actions.
2. Far beyond a norm in quantity or amount or degree; to an utmost degree.
3. Most distant in any direction.
4. Of the greatest possible degree or extent or intensity; SYN. utmost, uttermost.